// Copyright 2000-2017 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
package qunar.tc.decompiler.struct.attr;

import qunar.tc.decompiler.code.CodeConstants;
import qunar.tc.decompiler.modules.decompiler.exps.*;
import qunar.tc.decompiler.struct.consts.ConstantPool;
import qunar.tc.decompiler.struct.consts.PrimitiveConstant;
import qunar.tc.decompiler.struct.gen.FieldDescriptor;
import qunar.tc.decompiler.struct.gen.VarType;
import qunar.tc.decompiler.util.DataInputFullStream;

import java.io.DataInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class StructAnnotationAttribute extends StructGeneralAttribute {
    private List<AnnotationExprent> annotations;

    @Override
    public void initContent(DataInputFullStream data, ConstantPool pool) throws IOException {
        annotations = parseAnnotations(pool, data);
    }

    public static List<AnnotationExprent> parseAnnotations(ConstantPool pool, DataInputStream data) throws IOException {
        int len = data.readUnsignedShort();
        if (len > 0) {
            List<AnnotationExprent> annotations = new ArrayList<>(len);
            for (int i = 0; i < len; i++) {
                annotations.add(parseAnnotation(data, pool));
            }
            return annotations;
        } else {
            return Collections.emptyList();
        }
    }

    public static AnnotationExprent parseAnnotation(DataInputStream data, ConstantPool pool) throws IOException {
        String className = pool.getPrimitiveConstant(data.readUnsignedShort()).getString();

        List<String> names;
        List<Exprent> values;
        int len = data.readUnsignedShort();
        if (len > 0) {
            names = new ArrayList<>(len);
            values = new ArrayList<>(len);
            for (int i = 0; i < len; i++) {
                names.add(pool.getPrimitiveConstant(data.readUnsignedShort()).getString());
                values.add(parseAnnotationElement(data, pool));
            }
        } else {
            names = Collections.emptyList();
            values = Collections.emptyList();
        }

        return new AnnotationExprent(new VarType(className).value, names, values);
    }

    public static Exprent parseAnnotationElement(DataInputStream data, ConstantPool pool) throws IOException {
        int tag = data.readUnsignedByte();

        switch (tag) {
            case 'e': // enum constant
                String className = pool.getPrimitiveConstant(data.readUnsignedShort()).getString();
                String constName = pool.getPrimitiveConstant(data.readUnsignedShort()).getString();
                FieldDescriptor descr = FieldDescriptor.parseDescriptor(className);
                return new FieldExprent(constName, descr.type.value, true, null, descr, null);

            case 'c': // class
                String descriptor = pool.getPrimitiveConstant(data.readUnsignedShort()).getString();
                VarType type = FieldDescriptor.parseDescriptor(descriptor).type;

                String value;
                switch (type.type) {
                    case CodeConstants.TYPE_OBJECT:
                        value = type.value;
                        break;
                    case CodeConstants.TYPE_BYTE:
                        value = byte.class.getName();
                        break;
                    case CodeConstants.TYPE_CHAR:
                        value = char.class.getName();
                        break;
                    case CodeConstants.TYPE_DOUBLE:
                        value = double.class.getName();
                        break;
                    case CodeConstants.TYPE_FLOAT:
                        value = float.class.getName();
                        break;
                    case CodeConstants.TYPE_INT:
                        value = int.class.getName();
                        break;
                    case CodeConstants.TYPE_LONG:
                        value = long.class.getName();
                        break;
                    case CodeConstants.TYPE_SHORT:
                        value = short.class.getName();
                        break;
                    case CodeConstants.TYPE_BOOLEAN:
                        value = boolean.class.getName();
                        break;
                    case CodeConstants.TYPE_VOID:
                        value = void.class.getName();
                        break;
                    default:
                        throw new RuntimeException("invalid class type: " + type.type);
                }
                return new ConstExprent(VarType.VARTYPE_CLASS, value, null);

            case '[': // array
                List<Exprent> elements = Collections.emptyList();
                int len = data.readUnsignedShort();
                if (len > 0) {
                    elements = new ArrayList<>(len);
                    for (int i = 0; i < len; i++) {
                        elements.add(parseAnnotationElement(data, pool));
                    }
                }

                VarType newType;
                if (elements.isEmpty()) {
                    newType = new VarType(CodeConstants.TYPE_OBJECT, 1, "java/lang/Object");
                } else {
                    VarType elementType = elements.get(0).getExprType();
                    newType = new VarType(elementType.type, 1, elementType.value);
                }

                NewExprent newExpr = new NewExprent(newType, Collections.<Exprent>emptyList(), null);
                newExpr.setDirectArrayInit(true);
                newExpr.setLstArrayElements(elements);
                return newExpr;

            case '@': // annotation
                return parseAnnotation(data, pool);

            default:
                PrimitiveConstant cn = pool.getPrimitiveConstant(data.readUnsignedShort());
                switch (tag) {
                    case 'B':
                        return new ConstExprent(VarType.VARTYPE_BYTE, cn.value, null);
                    case 'C':
                        return new ConstExprent(VarType.VARTYPE_CHAR, cn.value, null);
                    case 'D':
                        return new ConstExprent(VarType.VARTYPE_DOUBLE, cn.value, null);
                    case 'F':
                        return new ConstExprent(VarType.VARTYPE_FLOAT, cn.value, null);
                    case 'I':
                        return new ConstExprent(VarType.VARTYPE_INT, cn.value, null);
                    case 'J':
                        return new ConstExprent(VarType.VARTYPE_LONG, cn.value, null);
                    case 'S':
                        return new ConstExprent(VarType.VARTYPE_SHORT, cn.value, null);
                    case 'Z':
                        return new ConstExprent(VarType.VARTYPE_BOOLEAN, cn.value, null);
                    case 's':
                        return new ConstExprent(VarType.VARTYPE_STRING, cn.value, null);
                    default:
                        throw new RuntimeException("invalid element type!");
                }
        }
    }

    public List<AnnotationExprent> getAnnotations() {
        return annotations;
    }
}